My ISP says I have an 8Mbit connection, I think it’s lower – how can I check?

The first thing to remember with quoted internet connection speeds is that they’re actually a theoretical maximum, and at times may well be much lower than the quoted maximum, this can be for a number of reasons, but four of the most common are:

Contention – This is a term used to describe the number of people that are using the same broadband connection as you, and is often quoted as a ratio e.g. 50:1, this means that you are sharing the connection with 49 other people, and if many of those are accessing the internet at the same time as you, then your speeds will drop. ISP’s can operate in this manner because the chances of all users being connected at the same time are fairly slim, and they work on an ‘average use’ policy. Most domestic ISP in the UK run with 50:1 contention ratios, but it’s possible to obtain 20:1 by paying a little extra.

Slowest link – When you make a connection to a website, FTP server, or any other part of the internet, you are effectively forming a chain of connections to your destination. E.g. You connect to your ISP, who in turn connects to the internet backbone via a series of connections and routers, and then onto your destination. This connection will only run at the speed of the slowest link, so if you are connecting to a remote computer that only has a 1Mbps connection to its ISP or internet, then it doesn’t matter how fast your connection is, that maximium speed will never be more than 1Mbps.

Internet Sharing – Do you have a home or office network with more than one PC sharing the connection? If you do then this will also affect the speed at which you can connect. In a similar way to contention, if you have a 2Mbps connection and then add 4 PC’s to your connection via a network, and connect them all to the internet, they all share the 2Mbps connection, so in theory you will only get 0.5Mbps if they are all running flat out at once.

High Usage – Many cheaper broadband deals have a usage cap that limits how much you can download each month. They also have ‘fair use’ policies, which means that if you download too much they can slow down your connection speed. A common cause of excessive usage is peer-to-peer software and music / video downloading.

Don’t forget that each of these can occur in isolation, or in combination, so if you have all three scenarios at once you could be getting a fairly slow connection indeed.

If after taking all this into account you still think that you’re getting a slower connection than you should, check out www.adslguide.org.uk/tools/speedtest.asp where you can download some tools to help you check your actual connection speed.